MIMXRT1176支持8位列地址的SDRAM器件W9864G6

    MIMXRT1176的开发板配套的 SDRAM是W9825G6KH，对应的列地址是9位的。

    MIMXRT1176支持的列地址是 8/9/10/11/12位。

    SDRAM 替换成 W9864G6后，Column地址变为 8位的。

    SDK中例程目录 evkmimxrt1170driver_examplessemcsdramcm7，修改semc_sdram.c文件配置如下。

status_t BOARD_InitSEMC(void)

{

    semc_config_t config;

    semc_sdram_config_t sdramconfig;

    uint32_t clockFrq = EXAMPLE_SEMC_CLK_FREQ;

    /* Initializes the MAC configure structure to zero. */

    memset(&config, 0, sizeof(semc_config_t));

    memset(&sdramconfig, 0, sizeof(semc_sdram_config_t));

    /* Initialize SEMC. */

    SEMC_GetDefaultConfig(&config);

    config.dqsMode = kSEMC_Loopbackdqspad; /* For more accurate timing. */

    SEMC_Init(SEMC, &config);

    /* Configure SDRAM. */

    sdramconfig.csxPinMux           = kSEMC_MUXCSX0;

    sdramconfig.address             = 0x80000000;

    sdramconfig.memsize_kbytes      = 1 * 8 * 1024;       /* 8MB*/

    sdramconfig.portSize            = kSEMC_PortSize16Bit; 

    sdramconfig.burstLen            = kSEMC_Sdram_BurstLen8;

    sdramconfig.columnAddrBitNum    = kSEMC_SdramColunm_8bit;

    sdramconfig.casLatency          = kSEMC_LatencyThree;

    sdramconfig.tPrecharge2Act_Ns   = 15; /* tRP 15ns */

    sdramconfig.tAct2ReadWrite_Ns   = 15; /* tRCD 15ns */

    sdramconfig.tRefreshRecovery_Ns = 70; /* Use the maximum of the (Trfc , Txsr). */

    sdramconfig.tWriteRecovery_Ns   = 2;  /* tWR 2ns */

    sdramconfig.tCkeOff_Ns =

        42; /* The minimum cycle of SDRAM CLK off state. CKE is off in self refresh at a minimum period tRAS.*/

    sdramconfig.tAct2Prechage_Ns       = 40; /* tRAS 40ns */

    sdramconfig.tSelfRefRecovery_Ns    = 70;

    sdramconfig.tRefresh2Refresh_Ns    = 60;

    sdramconfig.tAct2Act_Ns            = 2; /* tRC/tRDD 2ns */

    sdramconfig.tPrescalePeriod_Ns     = 160 * (1000000000 / clockFrq);

    sdramconfig.refreshPeriod_nsPerRow = 64 * 1000000 / 8192; /* 64ms/8192 */

    sdramconfig.refreshUrgThreshold    = sdramconfig.refreshPeriod_nsPerRow;

    sdramconfig.refreshBurstLen        = 1;

    sdramconfig.delayChain             = 6; /* For all tempeatures. */

    return SEMC_ConfigureSDRAM(SEMC, kSEMC_SDRAM_CS0, &sdramconfig, clockFrq);

}

static void SEMC_SDRAMReadWrite8Bit(void)

{

    uint32_t index;

    uint32_t datalen = SEMC_EXAMPLE_DATALEN;

    uint8_t *sdram   = (uint8_t *)EXAMPLE_SEMC_START_ADDRESS; /* SDRAM start address. */

    bool result      = true;

    PRINTF(" SEMC SDRAM Memory 8 bit Write Start, Start Address 0x%x, Data Length %d ! ", sdram, datalen);

    memset(sdram_writeBuffer, 0, sizeof(sdram_writeBuffer));

    memset(sdram_readBuffer, 0, sizeof(sdram_readBuffer));

    /* Prepare data and write to SDRAM. */

    for (index = 0; index < datalen; index++)

    {

        sdram_writeBuffer[index] = index % 0x100;

        sdram[index]             = sdram_writeBuffer[index];

    }

    PRINTF(" SEMC SDRAM Read 8 bit Data Start, Start Address 0x%x, Data Length %d ! ", sdram, datalen);

#if defined(CACHE_MAINTAIN) && CACHE_MAINTAIN

    DCACHE_InvalidateByRange(EXAMPLE_SEMC_START_ADDRESS, 4U * SEMC_EXAMPLE_DATALEN);

#endif

    /* Read data from the SDRAM. */

    for (index = 0; index < datalen; index++)

    {

        sdram_readBuffer[index] = sdram[index];

    }

    PRINTF(" SEMC SDRAM 8 bit Data Write and Read Compare Start! ");

    /* Compare the two buffers. */

    while (datalen--)

    {

        if (sdram_writeBuffer[datalen] != sdram_readBuffer[datalen])

        {

            result = false;

            break;

        }

    }

    if (!result)

    {

        PRINTF(" SEMC SDRAM 8 bit Data Write and Read Compare Failed! ");

    }

    else

    {

        PRINTF(" SEMC SDRAM 8 bit Data Write and Read Compare Succeed! ");

    }

}

    备注：在 MIMXRT1050 MCU 上只支持9/10/11/12位，不支持 8位的。

    SDRAM 配置参考文档：

https://www.nxp.com.cn/docs/en/nxp/application-notes/AN12026.pdf

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审核编辑 ：李倩